Composition of matter and method of making same



Patented July 2, 1946 @OMPOSITION MATTER AND METHOD OF MAKING SAME Melvin Dc Groote, Univers' y City, Bernhard Keiser, Webster Groves, and Arthur F. Wirtel,

Kirkwood, Mo.,

assignorsto Pctrolite Corporation, Ltd., Wilmington,'Del., a corporation of Delaware No Drawing. Application July 1, 1943, I

Serial No. 493,150

This invention relates to a new chemical product or composition of matter, our present application being a continuation-in-part of our pending application Serial No. 463,440, filed October 26,

1943, which subsequently matured as 'U. S. Patent 5 No. 2,363,506, dated November 28, 1944.

One object of our invention is to provide a new chemical product or compound that is particularly adapted for use as a'demulsifier in the resolution of crude oil emulsions.

Another object of our invention is to provide a practicable method for manufacturing said new chemical product-or compound. i

Although one of the primary objects ofour invention is to provide a new compound or composition of matter that is an efficient demulsifier for crude oil emulsions of the water-in-oil type, the said compound or composition of matter is adapted for use in other arts as hereinafter indi: cated. It also may have additional uses in various other fields which have not yet been investigated. Some of the additional uses of the new chemical product or compound herein described are as follows: as a break inducer in the doctor treatment of sour hydrocarbon distillates and the like; as a treating agent in a flooding process for recovering oil from subterranean oil-bearing Sands, and as a treating agent in aproce ss for preventin oil-in-water emulsions in the acidization of calcareous oil-bearing strata.

The composition of matter herein contemplated as such, and particularly for use as a demulsifier, is obtained by reaction between a polybasic carboxy acid, and particularly a dibasic car-boxy acid or its anhydride, and certain oxyacylated derivatives of ricinoleic acid, or more especia11y, derivativcs of the commonest ricinoleic acid ester, to wit, triricinolein or castor oil,

Reference is made to our three U. 5'. Patents Nos. 2,340,305, 2,340,306 and 2,340,307, all dated February 1, 1944.

Our first above mentioned patent describes a drastically-oxidized hydroxyacetylated 'ricinoleic acid compound selected from the class consisting of castor oil, triricinol'ein,diricinolein, monoricim olein, superglycerinatedcastoroil, castor oil estolides, polyricinoleic acid, and ricinoleic acid,

The second abovementioned patent describes a hydroxyacetylated, drastically-oxidized, ricinoleic acid compound selected from the class consisting of blown castor oil, blown triricinolein, blown diricinolein, blown monoricinolein, blown superglycerinated castor oil, blown polyricinoleic acid, and blown castor. oil estolides.

7 Claims.- (01. 260-406) The last, abovem'entioned patent describesa- 7' hydroxyacetylated, drastically-oxidized, dehydrated-ric-inoleic acid compound seelcted from the class consisting of drastically-oxidized, dehydrated castor oil; drastically-oxidized, dehydrated triricinolein; drastically-oxidized, dehydrated diricinolein; drastically oxidized, dehydrated monoricinolein; I drastically-oxidized, dehydrated ricinoleic acid drastically-oxidized, dehydrated polyricinoleic acid; and the estolides of drastically-oxidized, dehydrated castor oil.

'In the present instance, materialsof the kind described in said aforementioned co-pending applications ardemployed as intermediates for the manufacture of more complex compounds or mixtures' of'compounds. In other words, the oxyaoetylat'ed ricinoleic acid derivatives of the kind previously described are treated with polybasic carbo'xy acids,=such as oxalic acid, citric acid, tartaricacid, succinic acid, adipic acid, maleic acid, fumaric' acid, citraconic acid, phthalic acid, or the functional equivalents of such acids as, for example, the'anhydrid es, to form products of particular value when used as demulsifiers for oilfield emulsions. We particularly prefer to use dibasic acids, and especially such dibasic acid or anhydrides which have 8 carbon atoms or less.

As far as we are aware, the raw materials used as reactants in the present instance for chemical combination with polybasic carboXy acids are described only in the aforementioned co-pending applications.

For completeness of description, it appears necessary to refer to such co-pending applications; and what is said hereinafter is taken in substantially verbatim form from said copending applications.

. PREPARATION OF RAW MATERIAL, TYPE 1 (DrasticaZZy-oxidieed, hydroxyccetylcted rz'cznoleic acid compounds) It is well known that oxidized oils can be obtained from castor oil, ricinoleic acid and various derivatives of ricinoleic acid, such as monoricinolein, diricinolein, and polyricinoleic acids They are produced by the common practiceof blowing or oxidizing castor oil and similar fatty oils or acids, particularly non-drying unsaturated fatty ,oils, means of a gaseous medium, such as air, oxygen, ozone, or ozoniz'ed air. The gaseous mediumsuch as air, may be moist or dry and the oxidation may take place int he presence or absence of a catalyst. The catalyst may be of a metallic type, such as lead vricinoleate, cobalt ricinoleate;-mamganese ricirroleate, etc; or it may be of the organic type which produces peroxide, such as alpha-pinene, linseed oil, etc. Oxidation may take place at atmospheric pressure or superatmospheric pressure, i. e., pressures up to or including 200 pounds gauge pressure, and at any temperature slightly above the boiling point of water, for instance, 120 C. up to any temperature which does not produce undue decomposition by pyrolytic reaction.

The time of blowing may be fairly brief, for example, 8-10 hours; or it may be quite extensive, for instance, as long as 101214 days, the longer time periods being employed generally when the temperature is just slightly above the boiling point of water, and when oxidation is with air at atmospheric pressure.

One method of preparing drastically-oxidized 'castor oil is described in U. S. Patent No. 2,023,-

979, dated December 10, 1935, to Stehr. Also see U. 5. Patent No. 2,183,487, dated December 12, 1939, to Colbeth;

Thus, the sameconventional procedure or procedures employed for oxidation of castor oil or similar compounds is equally suitable for the blowing or oxidation of hydroxyacetylated triricinolein. In most instances, the period of oxidation may be somewhat longer, although it is also possible to obtain satisfactory products, in which the period of oxidation is somewhat reduced in comparison with the oxidation of castor oil or triricinolein under the same conditions. The application of oxidation is so similar to or identical with that of castor oil, that any differences of manipulation which may be required are perfectly apparent in the ordinary conduct of the process. For instance, if one attempts to oxidize hydroxyacetylated castor oil to obtain the same viscosity as an oxidized castor oil, and if at the 'end of the predetermined period, the viscosity or other index indicates under-oxidation, naturally, the process is continued until the same or a comparable degree of oxidation is obtained. Similarly, in the conventional blowing of castor oil. the last stage of oxidation is somewhat critical and sometimes the period of blowing must be shortened. If, during the oxidation of hydroxyacetylated castor oil, there happens to be an increased or intensive period of reaction, obviously only the ordinary precautions need be taken to prevent over-oxidation. Except for the difference in molecular weight, hydroxyacetylated castor oil presents the same degree of unsaturation as castor oil, and thus the degree of oxidation can be measured or atleast approximated, by the percentage reduction in iodine value, simultaneously with the increase in viscosity.

The production of hydroxyacetylated castor oil iscomparatively simple and is comparable to the manufacture of acetylated castor oil, ex-

cept that hydroxyacetic acid appears to be more reactive than acetic acid, for instance, any suitably selected amount of castor oil may be treated with the appropriate amount of hydroxyacetic acid under conditions to promote esterification and remove any water formed. The usual procedures for promotion of esterification are well known, and involve one or more of the following: Employment of a temperature high enough to eliminate any water formed, for instance, 120 180 C.; sometimes the presence of a strong acid, such as a benzene-sulfonic acid in small amounts acts as a catalyst; sometimes it is expedient to pass an inert dried gas through the reacting mixture; at other times esterification may be conducted in the presence of a high boiling waterinsoluble solvent, such as xylene or the like, which assists in removing the water in the form of vapors; the condensate soderived, both from the water vapor and solvent vapor is separated by gravity; and the solvent returned to the reacting chamber for further use.

The selection of suitable amounts of reactants in the manufacture of hydroxyacetylated castor oil is, of course, simple. Castor oil may be analyzed for its tririncolein content by determination of its hydroxyl or acetyl value. Such determination, of course, includes any hydroxy acid compounds other than ricinoleic acid present, but this is immaterial for the present purpose. On the average, castor oil will indicate -92% of triricinolein. For convenience, in the present instance, one may consider triricinolein as if it were a trihydric alcohol, and thus, one may obtain monohydroxyacetylated triricinolein; di-hy droxyacetylated triricinolein, and tri-hydroxyacetylated triricinolein. For practical purposes, of course, there is no economical justification for trying to obtain a technically pure triricinolein and subjecting such material to hydroxyacetylation instead of employing castor oil.

Thus, the product particularly contemplated as a reactant in the present instance, is the compound or compounds obtained by the hydroxyacetylation of castor oil. For purposes of convenience, reference will be made to monohydroxyacetylated castor oil, di-hydroxyacetylatedcastor oil, and tri-hydroxyacetylated castor oil. Examination of the reaction between hydroxyacetic acid and castor oil indicates that water i formed and must be removed. Actually, the water formed may not necessarily be removed instantly, and thus, may undergo certain other obvious reactions. Likewise, for reasons of economy, it may be desirable to use a highly concentrated hydroxyacetic acid instead of the anhydrous material as the selected reactant. In such instances, the water would readily enter into hydrolytic reaction with the castor oil, and thus, the product or composition which is actually acetylated may even contain glycerol, in addition to triricinolein. It is not intended, in the present instance, to claim the product obtained by oxidation of hydroxyacetylated glycerol, but it is to be noted that such material may be pres ent cogenerically, for reasons indicated. Earlier reference to the compounds herein contemplated, and particularly for use as a reactant, include the hydroxyacetylated derivatives of ricinoleic acid compounds. These are now suitably qualified to be limited to triricinolein, diricinolein, monoricinolein, and ricinoleic acid, and most particularly, the cogeneric mixture obtained by the hydroxyacetylation of castor oil, including specific members mentioned subsequently.

Although it is believed that, in view of what has been said, no further description is necessary in regard to the manufacture of hydroxyacetylated castor oil, the following examples are included by way of illustration:

HYnRoxYAcE'rYLA'rEn CASTOR OIL Example 1 1,000 pounds of castor oil (triricinolein content 88%) is treated with 111 pounds of concentrated hydroxyacetid acid containing 30% of water. The reaction is conducted at -180 degrees centigrade for approximately 6 hours. Completeness of reaction is indicated by the fact that HFYDROXYACETYLATED CASTOR OIL Example 2 The same procedure is employed as in Example l, preceding, except that twice the amount of hydroxyacetic acid is employed so as to obtain a di-hydroxyacetylated castor oil.

HYmzoxYAonrYLArEn CASTOR OIL Example 3 The same procedure is followed as in Example 1, preceding, except that three times the amount of hydroxyacetylated castor oil is employed so as to yield a substantially tri-hydroxyacetylated castor oil.

HYDROXYACETYLATED CASTOR 011.

Example 4 The same procedure is followed as in Examples 1 to 3, preceding, except that anhydrous hydroxyacetic acid is employed and water is removed immediately upon formation. The product so obtained represents hydroxyacetylated castor oil, or more especially, hydroxyacetylated triricinolein, in the presence of a minimum amount of hydroxyacetylated cogeners.

It is well known that the exact composition of ordinary oxidized castor oil is not known. This has been a matter of comment from time to time in the literature, including the patent literature dealing with arts in which blown castor oil is contemplated. However, it is obvious that the nature of the products obtained by oxidation of hydroxyacetylated triricinolein or castor oil, must be significantly different from those obtained by the oxidation of castor oil. There are a number of reasons for this statement. One reason is the fact that oxidation, in both instances, involves the alcoholic hydroxyl radical. In the case of castor oil or triricinolein all three alcoholic radicals present are secondary alcoholic radicals. In the case of hydroxyacetylated castor oil, at least one of the three alcoholic radicals present are primary alcoholic radicals, and all three may be primary alcoholicradicals. It is one of the fundamental principles of organic chemistry that the oxidation of primary alcohols yields different products than are obtained by the oxidation of secondary alcohols. In view of this single concept alone, it is obvious that oxidized hydroxy-' acetylated triricinolein or castor oil must be of a difierent nature than ordinary oxidized castor oil.

In examining the chemical structure of hydroxyacetic acid, it is instantly recognized that the hydroxyl radical present has replaced an alpha-hydrogen atom, and thus, in the light of the theory of electronegativity, must be particularly susceptible to reaction. This points to a reactiveness on the part of this particular radical which would not necessarily be enjoyed by any primary alcoholic radical.

Then too, previous reference has been made to the fact that one need not employ anhydrous hydroxyacetic acid, but one may employ a concentrated aqueous solution of the kind available commercially. Thus, water enters as a reactant, even though not necessarily so selected. Hence, ultimately one may be concerned with the oxidation of the cogeneric mixture previously described in detail. Incidentally, in such cogeneric mixture, not only may ricinoleic acid be present, as has been pointed out, but one may also have a polyricinoleic acid, such as diricinoleic acid, trii'icinoleic acid, etc. Such polyricinoleic acids are included within the scope of the expression ricinoleic acid compound previously employed.

DRAsTIcALLY-OxInIzEn, HYDROXYACETYLATED CAs'roR 011.

Example 1 1,000 pounds of a material of the kind described under the heading Hydroxyacetylated castor oil, Example 1, preceding, is subjected to oxidation in the same conventional manner as employed fOr castor oil. The temperature employed is C., and the time approximately 223 hours. At the end of a period of oxidation, the product shows a marked increase in viscosity. The usual analytical determination such as are conventionally employed in connection with the examination of blown castor oil, indicate that drastic oxidation has taken place. The values, so determined, may be conveniently compared with the similar values determined on the hydroxyacetylated castor oil prior to oxidation.

DRASTICALLY-OXIDIZED, HYDROXYACETYLATED CAsToR OIL Emample 2 DRASTICALLY-OXIDIZED, HYDROX'YACETYLATED CASTOR OIL Example 3 The same procedure is followed as in Example 1, preceding, except that one employs as an intermediate material for oxidation the particular hydroxyacetylated castor oil described under the heading Hydroxyacetylated castor oil, Example 3, preceding.

DR-ASTICALLY-OXIIJIZED, HYDROXYACETYLATED CASTOR OIL Example 4 The same procedure is followed as in Example 1, preceding, except that one employs as an intermediate material for oxidation the particular hydroxyacetylated castor oil described under the heading Hydroxyacetylated castor oil, Example 4, preceding.

Nothing that has been said previously is intended to suggest that one may not use chemically pure or technically pure triricinolein as a reactant instead of castor oil. It may be used, if desired. Furthermore, one may obtain or prepare diricinolein, either pure or of a technical grade, and such product may be converted into the monoor poly-hydroxyacetylated derivative. The same applies to monoricinolein. Mono-hydroxyacetylated ricinoleic acid may also be employedr-For obvious reasons, however, nothing i taken place.

ordinarily gained by using any raw material other than castor oil, and we have found castor oil to yield much more efiective demul'sifiers than the other materials referred to. Thus, our preference, by far, is to employ castor oil as a reactant.

In view of what has been said, it is obvious that in the hereto appended claims there cannot be any satisfactory mean of characterizing the products, as such, or for use as demulsifiers, except in terminology, which is related to the method of manufacture.

The expression "drastically-oxidized, or drastic oxidation, as employed in the hereto appended claims, refers to gaseous oxidation by means of an oxygen-containing medium. Such expression does not contemplate wet oxidation, or oxidation by means of permanganate, or other comparable oxidizing agents.

It is furthermore understood that hydroxy: acetylation can be conducted by means of the chemical equivalent of hydroxyacetic acid, as well as the acid itself, for example, the anhydride or acylchloride.

PREPARATION or RAW MATERIAL, TYPE 2 (Hydroacyacetylated, drasticallymridized risinoleic acid compounds) Mild oxidation, 1. e., oxidation, as exemplified by the exposure of a film of castor oil to air, for: an extended period of time, such as weeks, or even month (see Chemical Technology and Analysis of Oils, Fats, and Waxes, by Lewkowitsch, sixth edition, volume 2, page 406), produces relatively small modifications of certain im portant indices, such as the iodine value, the acetyl value, and the saponification value. If drastic oxidation takes place, either by continued mild oxidation or by more vigorous oxidation from the very beginning of the reaction, a induced by either a higher reaction temperature. or the presence of a catalyst, then there is ob-- tained an oxidized oil having characteristics which clearly indicate that drastic oxidation has These indices of drastic oxidation are a relatively low iodine value, such a 70 or less, and may be a low as 40, or thereabouts; a saponification value of 215 to 283, or thereabouts; an acetyl value of approximately 160-200; an increased viscosity such that the material may be hardly mobile at ordinary temperatures; a specific gravity of almost one, or a trifle over one at times; an increased refractive index; and, in the absence of other coloring matter, a yellow to deep orange color. The color at times may be a questionable index, since some oxidized castor oils are bleached to make them particularly adaptable for use as plasticizers in light colored resinoid bodies.

Drastically-oxidized castor oil can be repared by well known methods, or such products can be purchased in the open market under various trade names, such as blown castor oil, blended castor oil, blended bodied castor oil, processed castor oil, oxidized castor oil, heavy castor oil, viscous castor oil, etc. These various trade names appear to be applied to drasticallyoxidized castor oils which differ merely in degree but not in kind.

The color of these oils is still pale or light colored, in comparison with the oil from which they have been derived. Usually they are fairly transparent, particularly in reasonably thin layers, for instance, an inch or less. Such oils represent greater or lesser degrees of partial oxidation in the sense that there is a drastic change in comparison with the change that takes place when a film of castor oil is exposed to air.

For the sake of differentiation, oils of the kind previously described will be referred to a pale blown, drastically-oxidized castor oils; and the same terminology is intended to apply to all other ricinoleic bodies of the kind hereinafter described. In addition to pale blown, drastically-oxidized castor oil, there is also another type of the kind described in U. S. Patent No. 2,023,979, to Stehr, dated December 10, 1935. The product described in said Stehr patent is characterized by the fact that drastic oxidation is continued past the stage where a pale blown oil is obtained, and where, as a matter of fact, a super oxidized product of almost semi-livery consistency is obtained.

Such products are usually much darker in color than the pale blown castor oils, for the reason that certain side reactions occur with the formation of dark colored by-products; and as a result, the transparency of the oil has greatly decreased or disappeared, and it is apt to be opaque in nature.

Attention is directed particularly to U. 8. Patent No. 2,183,487, dated December 12, 1939, to C01- beth, to the extent that it discloses details as to the oxidation of castor oil in a manner that is particularly desirable.

Our preference is to subject a pale blown castor oil of the following characteristics, to hydroxyacetylation:

The production of hydroxyacetylated blown castor oil or similar compounds i comparatively simple and is comparable to the manufacture of acetylated castor oil, except that hydroxyacetio acid or its equivalent, such as the anhydride or acyl chloride, is employed, and castor oil is replaced by the blOWn' product. In view of the acetyl or hydroxyl value of blown castor oil, the principal reaction is obviously an esterification reaction in which the reaction is hastened or caused to go to completion by removal of any water formed. The usual procedures for promotion of esterification are well known, and involve one or more of the following: Employment of a temperature high enough to eliminate any water formed, for instance, -180 0.; sometimes the presence of a strong acid, such as a benzene-sulfonic acid in small amounts acts as a catalyst; sometimes it is expedient to pass an inert dried gas through the reaction mixture; at other times esterification may be conducted in the presence of a high boiling water-insoluble solvent, such as xylene or the like, which assists in removing the water in the form of vapors; the condensate so derived, both from the water vapor and the solvent vapor, is separated by gravity; and the solvent returned to the reacting chamber for further use.

The selection of suitable amounts of reactants in the manufacture of hydroxyacetylated blown castor oil is, of course, simple. The blown oil may be analyzed so as to determine its hydroxyl oracetyl value. Such value may be interpreted on the basis of each fatty acid radical present. The acetyl value or hydroxyl value may not correspond exactly to the alcoholic hydroxyl radicals attached to each high molal fatty acid acyl radical, but such value does correspond, at least approximately. The reason is that there may be present anhydrides, or possibly some compounds of unknown nature or stability, which afiect the hydroxyl valu determination. For convenience in the present instance, one may consider blown triricinolein in the same manner that it is sometimes convenient to consider triricinolein, i. e., as if it were a trihydric alcohol, and thus, one may obtain mono-hydroxyacetylated, blown triricinolein, dihydroxyacetylated, blown triricinolein, and tri-hydroxyacetylated, blown triricinolein. For practical purposes, of course, there is no economical justification for obtaining a technically pure blown triricinolein and subjecting such material to hydroxyacetylation instead of employing blown castor oil.

Thus, the product particularly contemplated in the present instance is the compound or compounds obtained by the hydroxyacetylation of blown castor oil. For purposes of convenience, reference will be made to mono-hydroxyacetylated, blot 1 castor oil, di-hydroxyacetylated, blown castor oil, and tri-hydroxyacetylated, blown castor oil. Examination of the reaction between hydroxyacetic acid and castor oil, or hydroxyacetic acid and blown castor oil, indicates that water is formed and must be removed. Actually, the water formed may not necessarily be removed instantly, and thus, the water may undergo certain obvious reactions. Likewise, for reasons of economy, it may be desirable to use a highly concentrated hydroxyacetic acid instead of the anhydrous material as the selected. reactant. In such instances, the water would readily enter into hydrolytic reactions with the blown castor oil, and thus, the product or composition. which is actually hydroxyacetylated, may include compounds comparable to ricinoleic acid, polyricinoleic acid, monoricinolein and diricinolein. Generically, the expression superglycerinated fats, or supergIycerinated triricinolein refers to the mixture in which the monoglycerides and diglycerides are present. Specific terminology indicated in the present instance would be superglycerinated blown ,castor oil. Likewise, the acids and polymerized acids obtained from the blown castor oil, are sometimes referred to as a blown castor oil estolide. (See U. S. Patent No. 2,079,762, dated May 11, 1937, to De Groote and Keiser.) In addition to the other products formed by hydrolysis, glycerol must be included. It is not intended in the present instance to claim the product obtained by hydroxyacetylation of glycerol, but it is to be noted that such material may be present cogenerically, for reasons indicated. Earlier references to the compounds herein contemplated, and particularly for use as a demulsifier, include hydroxyacetylated derivatives of blown ricinoleic acid compounds, and such expression is now suitably qualified so as to be limited to blown castor oil, blown triricinolein, blown superglycerinated castor oil, and blown castor oil estolides, and other specific compounds mentioned subsequently. The preferred example is the cogeneric mixture-obtained by the hydroxyacetylation of blown castor oil. One may employ superglycerinated blown castor oil obtained by reactionbetween blown castor oil and glycerine, in the proportion of one or two moles of glycerol per 10 mole of blown castor oil. This simply means that the prduct is obtained by rearrangement instead of hydrolysis. Obviously, one may also employ technically pure blown monoricinolein, technically pure blown diricinolein, and technically pure blown ricinoleic acid.

Although it is believed, in view of what has been said, that no further description is necessary in regard to the manufacture of hydroxyacetylated blown ricinoleic acid compounds, the following examples are included by way of illustration:

HYDROXYACETYLATED, BLOWN CASTOR OIL Example 1 1,000 pounds of pale blown castor oil corresponding to the tabular specification above is treated with 111 pounds of concentrated hydroxyacetic acid containing 30% of water. The reaction is conducted at -180 C. for approximately 6 hours. Completeness in reaction is indicated by the fact that elimination of water practically ceases, decrease in acid value and hydroxyl value of mixture, and elimination of free hydroxyacetic acid. The procedure is conducted in the usual reaction vessel of the kind employed for esterification, and may be constructed of any material which is resistant to the reactants. The amount of hydroxyacetic acid selected in the present instance is calculated so as to give substantially a mono-hydroxyacetylated blown castor oil.

HYDROXYACETYLATED, BLOWN CASTOR OIL Example 2 The same procedure is employed as in Example 1, preceding, except that twice the amount of hydroxyacetic acid is used.

HYDROXYACETYLATED, BLOWN CASTOR OIL Example 3 The same procedure is followed as in Example 1, preceding, except that three times the amount of hydroxyacetic acid is employed so as to yield substantially a tri-hydroxyacetylated blown castor oil.

HYDROXYACETYLATED, BLOWN CASTOR OIL Example 4 PREPARATION OF RAW MATERIAL, TYPE 3 (A hydromyacetylated, drastically-oxidized, dehydrated ricinoleic acid compound) The same sort of procedure which is used to oxidize ricinoleic acid compounds which have not been subjected to pyrolytic dehydration, such as ordinar castor oil of commerce, may also be employed to oxidize dehydrated castor oil, or similar material of the kind herein intended as a primary raw material. Generally speaking, however, the following modifications should be kept in mind:

Su h materialsare apt to contain at least a significant amount of octadecadiene 9, ll-acid-l or its ester, which is recognized a a powerful catalyst for promoting oxidation of castor oil or that any of the usual procedures employed for oxidizing castor oil may be employed for oxidizing dehydrated castor oil, yet generally speaking, considerably less drastic conditions are required. Furthermore, the time element can be decreased greatly. The same sort of apparatus and the same sort of procedure is employed as in the case of conventional oxidation of castor oil.

Since dehydrated castor oil is already polymerized to a greater or lesser degree, and perhaps has initial viscosity considerably greater than that of castor oil, it is obvious that the final stages of oxidation must be carried out more cautiously, and that excessive oxidation may produce a solid or spongy or rubber-like material without previous indication of the imminent critical stage. In an event, the material, prior to oxidation, should be analyzed and oxidation should be conducted until there is a significant change, as indicated by increase in viscosity, change in such indices a iodine number, hydroxyl number, etc., all of which is obvious to those skilled in the art. As a matter of fact, unless one desires to do so, there is no need to oxidize such dehydrated eastor oil, insofar that various products of this kind are sold commercially and used in othe arts which have no particular connection with the usage herein contemplated.

Castor oil or similar materials of the kind described have been dehydrated, and such dehydrated materials used for various other purposes, for instance, as substitutes for drying oils, as plasticizers in the manufacture of resins, as in\ gredients entering into the compounding of insulating materials, etc. Generally speaking, the conventional procedure is to subject a quantity of castor oil to destructive distillation, approximately 250-310 C., and generally, 250-285 C., until at least 545% of the original volume has been removed as a distillate. Sometimes the procedure is conducted primarily to recover the distillate, due to its high content of heptaldehyde. Generally speaking, the lower limits of the material distilled off are approximately 840%, and the upper limits, possibl 15-23%. In some instances, pyrolysis is conducted in the presence of an added catalyst, which may permit the reaction, i. e., the degradation or destructive distillation, to take place at lower temperature; and sometimes vacuum is employed or both vacuum and a catalyst, Such procedure of subjecting a ricinoleic acid compound, and especially ricinoleic acid or castor oil, to a pyrolysis, is so well known that no further elaboration is required.

. However, for convenience, reference is made to the following patents, which clearly describe the procedure, and in some instances, point out at least some of the complicated chemical changes that take place: U. S. Patents Nos. 1,240,565, Harris, September 18, 1917; 1,749,463, Bertsch, March 4, 1930; 1,799,420, Holton, April 7, 1931; 1,886,538, Fanto, November 8, 1932; 1,892,258, Ufer, December 27, 1932; 2,156,737, Priester, May 2, 1939; 2,195,225, Priester, March 26, 1940; British, 306,452, Scheiber, May 9, 1930.

As to a comparative evaluation of various dehydration catalysts for castor oil, see Masloboino- Zhirovanya Prom. 16 No. 5/6, 33-8 (1940).

The products which we prefer to use as reactants in the present instance, are blown dehydrated castor oils having substantially'the following ldentifying characteristics within the ranges indicated:

Acid number 14.0 to 25.0 Saponification number 195 to 240 Iodine number 70 to 95 Hydroxyl number 63.0 to 80.0 Reichert-Meisel number Less than 5 Acetyl number 1. 60 to 75 Percent unsaponifiable matter Generally less than 3 Percent nitrogen 0.0 Percent S02 0.0 Percent ash Trace Specific gravity at 31 C About 0.9574 Refractive index at 31 C About 0.1495 Color Straw or light amber A specific example of a very desirable oxidized dehydrated castor oil for use in the practice of this invention and which is available in the open market, has approximately the following specific characteristics:

Acid number 18.1 Saponification number 216.5 Iodine number 83 Acetyl number 68 Hydroxyl number 71.4 Reichert-Meisel number 2.0 Percent unsaponifiable matter Less than 2.5 Percent nitrogen 0.0 Percent S02 0.0 Percent ash Trace Specific gravity at 31 C 0.9574 Refractive index at 31 C 0.4795

The above values or similar values are of assistance in indicating and characterizing a material of the kind herein contemplated. For instance, although the entire chemistry of the dehydration of castor oil isnot known, yet obviously, there must be a marked reduction in the acetyl or hydroxyl value, and simultaneously an increase in the iodine value. Also, such pyrolytic reaction tends to eliminate the low molal or volatile acids. On oxidation of such material, the acetyl value or hydroxyl value may stay constant or increase. But, in any event, the iodine value is reduced until it begins to approximate that of castor oil or rici-noleic acid prior to dehydration, or somewhat lower. The fact that the acetyl value or hydroxyl value does not increase proportionally with the drop in the iodine value is, of course, due to either the formation of ether type compounds, or oxides which do not give a hydroxyl or acetyl value, or else, due to the formation of ester acids or similar reactions. It is generally desirable that the iodine number of the drastically-oxidized dehydrated castor oil be not less than 70, that the saponification value be within the range to 200, and that the acetyl value be within the range of 60 to 75.

The production of hydroxyacetylated, drastically-oxidized, dehydrated castor oil, or a similar type of compound, is comparatively simple and is comparable to the manufacture of acetylated castor oil, except that hydroxyacetic acid appears to be more reactive than acetic acid, and instead of using castor oil, one employs drastically-oxidized, dehydrated castor oil as a reactant. Since drastically-oxidized, dehydrated castor oil is characterized by the presence of a hydroxyl group or groups, as indicated by the -13 hydrox-yl value or number, it is obvious that esterification must take place, and thus the reactant is conducted in such a manner and under such conditions as to promote esterification and remove any water formed. The usual procedures for promotion of esterification are well known, and involve one or more of the following: Employment of a temperature high enough to eliminate any water formed, for instance, 120- 180 0.; Sometimes the presence of a strong acid, such as a benzene-sulfonic acid in small amounts acts as a catalyst; sometimes it is expedient to pass an inert dried gas through the reacting mixture; at other times esterification may be conducted in the presence of a high boiling waterinsoluble solvent, such as Xylene or the like, which assists in removing the water in the form of vapors; the condensate so derived, both from the water vapor and solvent vapor, is separated by gravity; and the solvent returned to the reacting chamber for further use.

The selection of suitable amounts of reactants in the manufacture of hydroxyacetylated, drastically-oxidized, dehydrated castor oil or the like, is, of course, simple. One may select a drastically-oxidized, dehydrated castor oil corresponding, for example, to the type previously described by analytical values. The hydroxyl or acetyl value or-number includes the hydroxyl groups attached to each of the high molal acyl radicals present. The chemical changes occurring in the manufacture of drastically-oxidized, dehydrated castor oil indicate that the final product is, in

' essence, a glyceride, or at least, to the extent of a majority percentage. With this in mind, it is apparent that the hydroxyl groups may be distributed more or less uniformly in regard to the three high molal acyl radicals present in such glyceride. For convenience, in the present instance, one may consider such product as comparable to triricinolein, and as if it were a trihydric alcohol. From tricinolein one can obtain mono-hydroxyacetylated triricinolein, dihydroxyacetylated triricinolein, and tri-hydroxyacetylated triricinolein. Similarly, based on molar proportions. one can obtain a mono-hydroxyacetylated, drastically-oxidized, dehydrated triricinolein, a di-hydroxyacetylated, drasticallyoxidized, dehydrated triricinolein, and a trihydroxyacetylated, drastically-oxidized, dehydrated triricinolein. For practical purposes, of course, there is no economical justification for obtaining a technically pure triricinolein, subjecting such material to dehydration, and then to drastic oxidation, and finally to hydroxyacetylation. For practical purposes, we prefer to use castor oil as the initial raw material. Actually, one is not limited to the stoichiometric proportions, for we have found that a moderate excess of hydroxyacetic acid may be employed, over and above the amount indicated by the acetyl number or value.

Thus, the product particularly contemplated in the present instance, is the compound or compounds obtained by the hydroxyacetylation of drastically-oxidized, dehydrated castor oil. For purposes of convenience, reference will be made to mono-hydroxyacetylated, drastically-oxidized dehydrated castor oil, di-hydroxyacetylated, drastically-oxidized, dehydrated castor oil, and tri-hydroxyacetylated, drastically-oxidized, dehydrated castor oil. Examination of the reaction indicates that water is formed and must be removed. Actually, the water formed may not necessarily be removed instantly, and thus, may

i4 undergo certain other obvious reactions. Likewise, for reasons of economy, it may be desirable to use a highly concentrated hydroxyacetic acid instead of the anhydrous material as the selected reactant. In such instances, the water would readily enter into hydrolytic reactions with the drastically-oxidized, dehydrated castor oil, and thus, the product or composition which is actually hydroxyacetylated may include the estolicles, and also lower glycerides of the drastically-oxidized, dehydrated castor oil. Glycerol may also be present, but it is not intended in the present instance to claim the product obtained or reaction between hydroxyacetic acid and glycerol, but it is to be noted that such material may be present cogenerically, for reasons indicated.

The lower-glycerides are comparable to monoolein or di-olein, and are referred to generically, as superglycerinated fats, or more specifiically, superglycerinated triricinolein, or superg'lycerinated castor oil. In the present instance, the proper nomenclature would be superglycerinated, drastically-oxidized, dehydrated castor oil. Actually, if one desired, such products or compounds need not be obtained by hydrolysis, but one could treat one mole of drastically-oxidized, dehydrated castor oil with one or tWo moles of glycerol in the customary manner, so as to cause rearrangement to take place, i. e., so as to obtain the lower glycerides.

Earlier reference to the compounds herein contemplated, and particularly for use as a demulsifier, included the hydroxyacetylated derivatives of drastically-oxidized, dehydrated ricinoleic acid compounds. In view of what has been said, such compounds are now suitably limited to drastically-oxidized, dehydrated castor oil, drasdehydrated triricinolein, drastically-oxidized, dehydrated diricinolein, drastically-oxidized, dehydrated mono-olein, and the estolides of drastically-oxidized, dehydrated castor oil, together with drastically-oxidized, dehydrated ricinoleic acid and polyricinoleic acid.

Although it is believed that in view of what has been said, that no further description is necessary in regard to the manufacture of hydroxyacetylated, drastically-oxidized, dehydrated castor oil, or similar compounds, the following examples are included by way of illustration:

tically-oxidized,

HYDROXYACETYLATED, DRAsTIoALLY-OxInIzEn, DE- HYDRATED CASTOR OIL Example 1 1,000 pounds of drastically-oxidized, dehydrated castor oil, comparable in chemical characteristics to the tabular specification appearing previously, is treated with 37 pounds of concentrated hydroxyacetic acid containing 30% of water. The selected amount is sufiicient to combine with onethird of the available hydroxyl radicals, as indicated by the acetyl value or number. The reaction is conducted at -180 C. for approximately 6 hours. Completeness in reaction is indicated by the fact that elimination of water practically ceases, decrease in acid value and hydroxyl value of mixture, and elimination of free hydroxyacetic acid. The procedure is conducted in the usual reaction vessel of the kind employed for esterification, and may be constructed of any material which is resistant to the reactants. The amount of hydroxyacetic acid selected in the present instance is calculated so as to give substantially a mono-hydroxyacetylated, blown, dehydrated castor oil.

HYDROXYACETYLATED, DRASTICALLY-OXIDIZED, Dr:- HYDRATED CASTOR OIL Example 2 The same procedure is employed as in Example 1, preceding, except that twice the amount of hydroxyacetic acid is employed so as to obtain a dihydroxyacetylated, blown, dehydrated castor oil.

HYDROXYACETYLATED, DRASTICALLY-OXIDIZED, DE- HYDRATED CASTOR OIL Example 3 HYDROXYACETYLATED, DRASTICALLY-OXIDIZED, DE- HYDRATED CASTOR OIL Example 4 The same procedure is followed as in Examples 1 to 3, preceding, except that anhydrous hydroxyactic acid is employed and water is removed immediately upon formation. The product so obtained represents hydroxyacetylated, blown, de-

hydrated castor oil, or more especially, hydroxyacetylated, blown, dehydrated triricinolein, in the presence of a minimum amount of hydroxyacetylated cogeners.

HYnRoxYAoErYLArEn, DRASTICALLY-OXIDIZED, DE-

HYDRATED CASTOR OIL Example 5 The same procedure is followed as in Examples 1 to 4, preceding, but instead of using the stoichiometric amount of hydroxyacetic acid to yield a completely hydroxyacetylated product, one employs an excess, for instance, a -20% excess of hydroxyacetic acid.

Nothing that has been said previously is intended to suggest that one cannot use chemically pure or, technically pure triricinolein as an initial raw material instead of castor oil. Furthermore, one may obtain or prepare diricinolein, either pure or of a technical purity, and such material may be employed as an initial raw material. Likewise, pure or technically pure monoricinolein or ricinoleic acid may be employed. For obvious reasons, however, nothing is ordinarily gained by using any initial raw material other than castor oil, and we have found castor oil to yield much more effective demulsifiers than the other materials referred to. Thus, our preference, by far, is to employ castor oil as the initial raw material, and to subject it to drastic oxidation and dehydration.

Having obtained suitable raw materials of the kind previously described, the next and final step is reaction with a polybasic carboxy acid, or its functional equivalent, such as the anhydride. Since compounds of the kind previously described invariably have an alcoholiform hydroxyl radical present, reaction with a polybasic acid or anhydride is simply an esterification reaction. The amount of polybasic carboxy acid or anhydride employed is a stoichiometrical equivalent to the hydroxyl groups present or a fraction thereof. This can be illustrated readily by reference to triricinolein, which may be considered as a polyhydric alcohol.

Thus, triricinolein may combine with one part, two parts, or three parts of a polybasic acid, such as phthalic acid, maleic acid, etc. In the presnt instance, one employs an amount of polybasic acid which is sufficient to convert completely the raw material considered as an alcohol into the corresponding ester or some fraction of such toichiometrical amount, as, for example, one-third or one-half such an amount. The method of esterification is relatively simple, and is the same procedure ordinarily employed for the esterification of similar alcohols, and particularly, for the esterification of ricinoleic acid, phthalic acid, maleic acid, succinic acid, or the like. This can be accomplished in a number of ways. For instance, the reactants may be heated to a fairl high temperature, provided the polybasic acid does not decompose, as, for example, a temperature of C. Any water which is formed is rapidly eliminated. Constant stirring is employed during the entire process, and particularly to prevent local overheating.

A second procedure involves passing a dried inert gas such as nitrogen through the reaction mass to hasten reaction and to help eliminate any water which ma be formed.

Another procedure is to add a small portion of a sulfonic acid, for instance, half a percent of benzene sulfonic acid or the like, to serve as a catalyst and hasten reaction.

Still another procedure is to add an insoluble high boiling inert solvent to the reaction mass and permit such solvent to reflux under conditions which help eliminate any water vapor, which may be removed after condensation. A condensed solvent is returned to the reaction chamber and may be removed after reaction is complete, or may be allowed to remain as a solvent in the final mass.

COMPOSITION or MATTER Example 1 A drastically-oxidized, hydroxyacetylated castor oil of the kind described under a previous subheading entitled Drastically-oxidized, hydroxyacetylated castor oil, Example 1 is analyzed to determine the acetyl or hydroxyl value. 1,000 lbs. of such material are then reacted with a suitable selected quantity of phthalic anhydride; for instance, 350 lbs. of phthalic anhydride will serve conveniently. The reaction is conducted in a reaction chamber at approximately 150-180 degrees for 4-10 hours. The reaction mass may be diluted with a suitable solvent while still warm, and is particularly effective as a demulsifier.

COMPOSITION or MATTER Example 2 The same procedure is followed as in Example 1, preceding, except that one employs instead of the material described under the sub-heading "Drastically-oxidized, hydroxyacetylated castor oil, Example 1, the particular varieties described under the same heading, but identified by Example 2, Example 3," or Example 4.

COMPOSITION or MATTER Example 3 The same procedure is followed as in Examples 1 and 2, preceding, except that one or more of the various hydroxyacetylated, blown castor oils described under the sub-headings Hydroxyacetylated, blown castor oil, Examples 1, 2, 3 and 4, are substituted for 1,000 lbs. of ricinolelc acid compounds used in the two examples preceding as raw materials.-

.part of the products COMPOSITION or MATTER Example 4 The same procedure is followed as in Composition of matter, Examples 1 and 2, preceding, except that one Or more of the various hydroxyacetylated, blown castor oils described under the sub-headings Hydroxyacetylated, drasticallyoxidized, dehydrated castor oil, Examples 1-5 is substituted for the 1,000 lbs. of ricinoleic acid compounds used in the Examples 1 and 2, preceding, as raw materials.

COMPOSITION or MATTER Example 5 The same procedure is followed as in Examples 1-4, preceding, except that maleic anhydride is substituted for phthalic anhydride.

COMPOSITION or MATTER Example 6 The same procedure is followed as in Examples 1-4, preceding, except that citraconic anhydride is substituted for phthalic anhydride.

Previous reference has been made to the fact that the raw materials employed in the present instance for reaction with polybasic acids may be considered in their simplest forms as alcohols, including polyhydric alcohols.

derived may be considered as fractional esters; and one type of fractional ester is characterized by the presence of one or more free carboxyl groups, and particularly derived from the polybasic carboxy acid.

As far as demulsification is concerned, we prefer to use the acidic type of fractional ester. Such type is readily prepared by using the properly selected, predetermined amount of polybasic carboxy acid or anhydride. The presence of the acidic group or groups is indicated by an acid value determination on the finished product.

Other uses for the herein described chemical compounds or products include application as plasticizers, in plastics, synthetic resins, etc., and particularly in the acetate type, i. e., the cellulose acetate, vinyl acetate and similar types.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is:

1. An ester derived by reaction between a reactive polybasic carboxy ac'd compound and a member of the class consisting of a drasticallyoxidized, hydroxyacetylated ricinoleic acid compound, a hydroxyacetylated, drastically-oxidized ricinoleic acid compound, and a hydroxyacetylated, drastically-oxidized, dehydrated ricinoleic acid compound; the hydroxyacetylated reactants being free from any reactive alcoholic hydroxyl Similarly, at least 7 18 radical other than the hydroxyl radical of the hydroxyacetyl group.

2. An ester derived by reaction between a reactive dibasic carboxy acid compound and a member of the class consisting of a drastically-oxidized, hydroxyacetylated ricinoleic acid compound, a hydroxyacetylated, drastically-oxidized ricinoleic acid compound, and a hydroxyacetylated, drastically-oxidized, dehydrated ricinoleic acid compound; the hydroxyacetylated reactants being free from any reactive alcoholic hydroxyl radical other than the hydroxyl radical of the hydroxyacetyl group.

3. An ester derived by reaction between a reactive dibasic carboxy acid compound having less than 9 carbon atoms, and a member of the class consisting of a drastically-oxidized, hydroxyacetylated ricinoleic acid compound, a hydroxyacetylated, drastically-oxidized ricinoleic acid compound, and a hydroxyacetylated, drasticallyoxidized, dehydrated ricinoleic acid compound; the hydroxyacetylated reactants being free from any reactive alcoholic hydroxyl radical other than the hydroxyl radical of the hydroxyacetyl group.

4. An ester derived by reaction between a reactive dibasic carboxy acid compound having less than 9 carbon atoms, and a drastically-oxidized, hydro-Xyacetylated ricinoleic acid compound; the hydroxyacetylated reactants being free from any reactive alcoholic hydroxyl radical other than the hydroxyl radical of the hydroxyacetyl group.

5. An ester derived by reaction between a reactive dibasic carboxy acid compound having less than 9 carbon atoms, and a hyroxyacetylated, drastically-oxidized ricinoleic acid compound; the hydroxyacetylated reactants being free from any reactive alcoholic hydroxyl radical other than the hydroxyl radical of the hydroxyacetyl group.

6. An ester derived by reaction between a reactive dibasic carboxy acid compound having less than 9 carbon atoms, and a hydroxyacetylated, drastically-oxidized, dehydrated ricinoleic acid compound; the hydroxyacetylated reactants being free from any reactive alcoholic hydroxyl radical other than the hydroxyl radical of the hydroxyacetyl group.

7. In the manufacture of esters of the kind described in claim 1, involving the step of esterifying a polybasic carboxy acid compound with a member of the class consisting of a drastically-oxidized, hydroxyacetylated ricinoleic acid compound, a hydroxyacetylated, drastically-oxidized ricinoleic acid compound, and a hydroxyacetylated, drastically-oxidized, dehydrated ricinoleic acid compound.

MELVIN DE GROOTE. BERNI-IARD KEISER. ARTHUR F. W'IRTEL. 

